\documentclass{article}
\usepackage{amssymb,amsmath,amscd,concmath}
\pagestyle{empty}
\begin{document}
\begin{equation*}
\sim \; \approx \; \simeq \; \cong
\le \; < \; \ll \; \gg \; \ge >
\equiv \; \not\equiv \; \ne \; \propto
\pm \; \mp
\end{equation*}
\end{document}
